... 1,2).Discussion In the murine polyamine homeostasis at least two cata-lytically active splice variants of the spermine oxidase enzyme are involved. The cytosolic mSMOa is the major isoform, while the mSMOl ... encoding at least nine splice variants, as well as biochemical characterization of the canonical alfaisoform (mSMOa), have been reported recently [10,11]. The subcellular localization of the catalytically ... targeting by means of transient expression in the murine neurobla-stoma cell line, N18TG2.AbbreviationsMPAO, maize polyamine oxidase; mPAO, mouse polyamine oxidase; hSMO, human spermine oxidase; ...